Many organizations make use of relatively large, shared documents stored in various formats, such as HTML (Hypertext Markup Language), Microsoft Word, PDF (Portable Document Format), and text, among others. For example, such large documents may include shared legal documents held by law firms or shared engineering documents held by engineering firms or corporations. Three important qualities of such documents discourage their use on conventional devices: (1) the documents can become quite large, (2) the documents are frequently modified, and (3) the documents may not be in a format that can be read and displayed by the particular device (including mobile devices) utilized be each client. In particular, many mobile devices today lag behind desktop devices in at least three areas: connectivity, storage, and functionality. For example, GPRS (General Packet Radio Service) communication exhibits a low-bandwidth, high-latency connection. Moreover, a typical low-end, conventional, mobile device may have about 32 MB of memory, which severely limits the size of documents that may be stored. Also, code or programs for accessing and viewing documents on many devices are non-existent. Moreover, some formats may render better than others due to user interface scaling issues. In addition, some document formats may utilize less memory to expand than others. All of these issues cooperate to discourage the widespread use of relatively large documents collaboratively on different, particularly mobile, devices.
Another issue with downloading, viewing, editing, and uploading relatively large documents on devices is the time required to download such a document. As an example, if a relatively large document is already downloaded on a device and only a small modification in the document is required, downloading the entire document can waste scarce resources of bandwidth, memory, time, and money (e.g., where a network charges by the amount of data transferred).
Conventional systems attempt to address these problems with file synchronization systems and methods. Conventional file synchronization solutions require that the entire document be replicated to a device. Although some PC-based applications go a step further to transcode the document into a format that the device can read, the problems with both of these conventional solutions are still numerous. For example, the wholesale synchronization of entire documents requires that all of the devices be able to store the entire contents of the document in limited amounts of memory, as discussed above. Moreover, modifying a small portion of the document will cause the entire document to be downloaded to the device. Because of the conventional low-bandwidth and high-latency characteristics of wireless networks (e.g. GPRS) and the conventional cost structure of paying per byte of transferred data, it becomes expensive (both monetarily and temporally) to download an entire document to a device. In another conventional example, individual pages of a lengthy document may be downloaded one-by-one to reduce the amount of data transferred at one time. This solution, however, is only applicable to streamable files (e.g., html files) and does not lend itself too well to editing by the client receiving the pages, often due to the differences between client devices and programs. Moreover, this process allows only for download of information, and does not provide for editing and uploading of client modifications. Another conventional system synchronizes data offline, to avoid the problems associated with an unreliable connection. This solution, however, fails to address the issues of inadequate storage and transfer time, which may still be a problem with offline synching because of large document sizes.
Unfortunately, these issues are not addressed by any conventional system. Accordingly, a solution that improves synchronization of large documents among multiple clients is desirable.